Adaptations of plants to harsh or unusual environments; plant physiological ecology and environmental biophysics; photosynthesis; water and nutrient relations; microclimate measurements in the field; natural isotopes.
Research in my laboratory ranges from the cell to the landscape and ecosystem levels, but with an emphasis on the whole-organism. A primary focus concerns how plants are adapted to their respective habitats and the development of mechanistic explanations for the observed distribution patterns of different species. Unusually harsh or extreme environments (e.g. deserts, alpine, forest understory) are often excellent choices for understanding plant adaptation and distribution. Measurements of photosynthesis, temperature, water and nutrient relations, and natural isotopes provide the foundation for understanding adaptations in physiological processes, as well as structural/functional relationships at the leaf, crown, canopy and stand levels.
Current projects are evaluating stress factors at the alpine treeline, including new tree seedlings and snowbank species; determination of sources and sinks for CO2 exchange across mountain/plain landscapes; effects of global warming on alpine treeline and the form and function of alpine plants; impacts of leaf form (anatomy, morphology, and orientation) on photosynthetic performance; the influence of leaf surface wetness (e.g. dewfall) on gas exchange and ecophysiology; winter photosynthesis in evergreen species and effects of accessory pigments (e.g. anthocyanin).
Akhalkatsi, M, O. Abdaladze, G. Nakhutsrishvili, and WK. Smith. 2006. Facilitation of seedling microsites by Rhododendron caucasicum extends the Betula litwinowii alpine treeline (Caucasus Mountains, Georgia). Artic, Anarct., Alp. Res, in press.
Johnson, DM and WK Smith. 2006. Low clouds and cloud immersion enhance photosynthesis in understory species of a southern appalachian spruce-fir forest. Amer J Botany: in press
Smith, WK and DM Johnson 2006. Biophysical effects of altitude on plant gas exchange. In Biophysical Plant Ecology: Perspectives and Trends. Brown Pubishing, in press.
Germino, MJ, NJ Hasselquist, T McGonigle, WK Smith, and PP Sheridan. 2006. Landscape- and age-based factors affecting colonization of conifer seedling roots at the alpine treeline. Can J Forest Research 36: 1-9.
Brodersen, CR, Germino, MJ, and WK Smith. 2006. Photosynthesis during an episodic drought in Abies lasiocarpa and Picea engelmannii across an alpine treeline. Artic, Antarct, & Alpine Research 38:34-41.
Johnson, DM, WK Smith, TC Vogelmann, and CR Brodersen. 2005. Leaf architecture and direction of incident light influence mesophyll fluorescence profiles. Amer J Botany 92:1425-1431
Johnson, DM and WK Smith. 2005. Photosynthesis and survival in high altitude, current-year seedlings of Abies fraseri in the southern Appalachian Mountains. Tree Physiol, 25: 1379-1387.
Hill, JP, CJ Willson, and WK Smith. 2005. Enhancedphotosynthesis and flower production in a sagebrush morphotype associated with animal burrows. Plant Ecology 177:1-12
Smith, WK, TM Vogelmann, and C Critchley (Eds.). 2004. (lead author on Chapters 1 and 11) Photosynthetic Adaptation: Chloroplast to Landscape. Ecological Studies 178, Springer, NewYork. 316 pp.
Smith, WK, MJ Germino, TE Hancock, DM Johnson. 2003. Another perspective on the altitudinal limits of alpine timberline. Tree Physiol.23:1101-1112.
Smith. WK, Vogelmann, TC, Bell, DT, DeLucia, EH, and KA Shepherd. 1999. Leaf Form and Photosynthesis. BioScience 47:785-793.